Calgary water restrictions could ease by week’s end

Calgary's latest water crisis could be close to an end, but the next few days will be the big test. Meanwhile, the province wants to do its own review.

Hundreds of millions of litres of water are again being pumped through the Bearspaw South feeder main, and if it holds and remains stable, Calgary water restrictions would be lifted by the end of this week.

The section of the water main that ruptured on Dec. 30 has been fixed, and water quality tests have so far indicated it is safe to drink.

On Wednesday morning, city crews turned on the first set of pumps from the Bearspaw treatment plant in the first of three gradual steps to repressurize the water main that typically transports 60 per cent of the city’s drinking water.

“Returning the Bearspaw South feeder main to service is a delicate process. We can’t guarantee there won’t be another break during this time,” Michael Thompson, the city’s general manager of infrastructure services, said Wednesday.

“So, we are proceeding very carefully and gradually to return this pipe into service safely.”

As 200 million litres of water flow through the pipe in a day, crews will closely monitor the entire line for any breaks or hot spots.

On Thursday morning, more pumps will be turned on and 225 million litres of water will flow to test the main.

If everything goes well, Friday morning will see the last of the pumps turned on, and 285 million litres of water will then rush through the pipe, which has been described as “fragile” and “sick” by the mayor.

“This is a significant step forward. It tells us the repair is holding, the system is responding as expected and the work is progressing safely,” Jeromy Farkas said.

“We know that this whole pipe is still sick, and we know we are still in uncharted territory, so we can’t breathe easy until the new pipe is in the ground and online, but we are almost at the end of this chapter.”

During recent monitoring of the repaired pipe, Thompson said two wire snaps were heard along the line while it was slowly repressurized but added they were “not in locations that are deemed critical.”

The pre-stressed concrete cylinder pipe (PCCP) used along most of the feeder main is made of concrete with steel wires wrapped tightly around it, but the wires have been found to fail and contribute to the catastrophic ruptures Calgary has experienced twice in less than two years.

Calgarians used 499 million litres of water on Tuesday, higher than the city’s “sustainable” goal of 485 million litres per day.

Stage 4 water restrictions remain in place.

“While the finish line is in sight, we need your help just a little bit longer to conserve water,” Sue Henry, the city’s chief of emergency management, said Wednesday.

Temporary repairs along the area of 16th Avenue N.W. where the break happened have mostly been completed, and lanes of traffic in both directions are now open.

However, westbound traffic is still limited to one lane for now, and reopening is happening in phases because that direction needs “more time to stabilize,” Henry said.

Crews will be back at the same section of the road in the spring to rip it up again and do repairs that can’t be done during the winter months.